This is a species (Hydrolycus wallacei) of Payara that was described in 1999. I have never heard it mentioned on these forums as a species kept in the hobby. Here's a link that has some further information and pictures about this and the other species of Payara.
http://www.acuteangling.com/Payara/payara-wallacei.html
http://www.acuteangling.com/Payara/payara-wallacei.html